The firefighters union does not want a panel of arbitrators to require that health care benefits for its membership be managed by a union-operated entity, a spokesperson said Thursday. Carving out firefighter health care from the City of San Antonio’s control into a separate trust was a proposal floated by the union during contract negotiations earlier this year. Such a trust would set its own benefits and premiums for members. The City balked then and this week at the idea. But the most recent union proposal – currently being vetted by three arbitrators who will decide the final terms of the union’s labor contract with the City – merely calls for an exploratory committee or working group to be established to discuss the possibility of a such a trust in the future, said Richard Poulson, an attorney representing the union.